Automatic choke for gun barrels



Jan' 20 1942' J. H. Kl'rzMlLLER AUTOMATIC CHOKE FOR GUN BARRELS Filed June 2, 1938 INVENTOR A l ER. 1,

T ORN Y Patented Jan. 20, 1942 AUTOMATIC CHOKE FOB. GUN BARRELS James H. Kitzmlller, Reading, Pa.

Application June 2, 1938, Serial No. 211,311

- Claims.

This invention relates to shot guns, and has particular reference to means constituting an automatic choke for constricting the discharge end of the gun barrel.

When in the eld or iiring at a close target,`

the barrel of a shot gun should be opened or unchoked to give a large pattern and to prevent blowing the target Ato pieces. When in the field and the game normally moving away from the shooter is missed by the rst shot, the automatic choke operated by the 'recoil of the lrst shot v,ill give distance and killing power to the second shot on the game which has naturally moved farther away. It has been found in practice that it is not practicable to adjust a choke by hand. Sighting is interrupted. The game is permitted to move farther away while this adjustment is being made by hand, and various other objections to hand-adjustable choke means have been found.

The object of the present invention is to provide automatic choke means for constricting the discharge end of the gun barrel to give distance and greater concentration of the charge.

A further object of the invention is to provide in an automatic choke device, means for locking the operative parts in their open or constricted position.

A still further object of the invention is to provide such automatic choke means with mechanism for quickly attaching or removing the same from the gun barrel.

According to the invention, the automatic choke means, which may be applied either to the end of the gun barrel per se or to the end of the gun barrel in the form of an attachment, has a barrel provided with a series of longitudinal slots at the discharge end thereof, a portion at the discharge end enlarged above the normal outer diameter and tapering to the normal diameter, a sleeve having a sliding t on the normal outer diameter of said barrel, and arranged upon the gun recoil to encompass said enlarged area to reduce the discharge diameter of said barrel. The

Figure 3 is a longitudinal sectional view taken on the line 3-3 of Figure 1,

Figure 4 is a vertical sectional view taken on ,the line 4-4 of Figure 3,

Figure 5 is an enlarged view showing the means for locking the choke sleeve in open or closed position, and

Figure 6 is a view similar to Figure3, and shows the end of a gun barrel per se adapted for incorporating the invention.

As illustrated in the drawing, the shot gun barrel II may be externally threaded Aas at I2 to receive the internally threaded sleeve i3 of a gun barrel extension I4, whose normal bore I6 is identical with the b'ore I1 of the gun barrel.

T-he extension I4 has a concentric shoulder I8 -nal thereof, and extending some distance backI from said discharge end. These slots 24 are of suicient width to permit the outer diameter of the shoulder I8 to be reduced to the diameter 2 I. The extension is provided with a peripheral slideway 25. A sleeve 21, whose inner diameter is such as to provide a sliding fit with the outer normal diameter 2I of the extension I4, ts over the same, and has a key 28 resting in a keyway 29, which said key is broken at 3l to allow the same to be sprung outward to slide over the shoulder I8, and spring into the slideway- 26. This extension'is provided with an enlargement 32, and, in turn, this enlargement has a hole- 33 into which a tool may be placed for bearing against the ends of the spring key 28 to spreadv the same so as to release it from the slideway 26, when it is desired to remove the sleeve 21 from the extension.

The extension I4 may be provided with a guideway 34 for the end 36 of a pin 31'. This pin may have a thumb piece 38 on its outer end. and a leaf spring 39 for placing tension against the movement of said pin.

The guideway 34 may have the forward well 4I and the rear Well 42 for receiving the enlarged end of the pin 31 to lock the sleeve 21 against movement from either the open or constricted position. Thisl pin 31 is, of course, manually operable, and provides. means to prevent the operation of the automatic choke when shooting at short range, or to provide a choke discharge when shooting at long range.

Figure 6 shows the movable sleeve 21 connected with the end of the gun barrel per se. This view shows the sleeve in a position to constrict the end of the gun barrel. In this instance, all the parts as herein described in connection with the extension placed on the gun barrel will be found except the extension and attending parts per se, and the end of the gun barrel may be provided with the shoulder I8, tapered part i9, and longitudinal slots 24, when new guns are built to incorporate this invention.

This invention has been tested over a long period of time, and has been found to give remarkable results; the gun recoil, commonly called the kick or kick back, pulling the barrel to the rear, so that the sleeve slides up the tapered portion I9 onto the shoulder I8 and Vautomatically provides a constricted barrel for the second shot.

Of course, the automatic choke device for gun barrels herein illustrated and described may be modied in various ways without departing from the invention herein set forth and hereafter claimed.

The invention is hereby claimed as follows:

1. A gun barrel having a normally uniform bore, an external tapered enlargement at the discharge end of said barrel, said barrel having slots extending inward from the discharge end thereof, and a sleeve-like member constructed and arranged to slide freely on said barrel and to automatically ride onto said tapered enlargement in response to the recoil of the gun to thereby constrict the discharge end of said bore.

2. A gun barrel having a normally uniform bore, an external tapered enlargement at the discharge end of said barrel, said barrel having slots extending inward from the discharge end thereof, a sleeve-like member constructed and arranged to slide freely on said barrel and to automatically ride onto said tapered enlargement in response to the recoil of the gun to thereby constrct the discharge end of said bore, and means for limiting the relative movement of said member on said barrel.

3. A gun barrel having a normally uniform bore, an external tapered enlargement at the discharge end of said barrel, said barrel having slots extending inward from the discharge end thereof, a sleeve-like member constructed and arranged to slide freely on said barrel and to automatically ride onto said tapered enlargement in response to the recoil of the gun to thereby constrict the discharge end of said bore, and means for locking said member in either position.

4. An automatic choke device for guns comprising a gun barrel having a normally uniform bore and an external periphery uniform except at the discharge end of said barrel which is provided with a tapered enlargement, longitudinal slots extending from the discharge end of said barrel. and a member constructed'and arranged for free sliding on the uniform periphery of said barrel and to automatically ride onto said enlargement for embracing the enlargement to restrict the outer end of the bore in response to the recoil of said gun.

5. An automatic choke vdevice for guns comprising a gun barrel having a normally uniform bore and an external periphery uniform except at the discharge end of said barrel which is provided with a tapered enlargement, a member constructed and arranged for free sliding on the uniform periphery of said barrel and to automatically ride onto said enlargement for em- `bracing the enlargement to restrict the outer end of the bore in response to the recoil of said gun, and means for preventing the member from leaving said barrel.

JAMES H. KITZMILLER. 

